There's yet another reason to ditch the sweet stuff: scientists have found Alzheimer’s disease could be caused by excess sugar.

A new study has established a “tipping point” link between the blood sugar glucose and the disease, meaning people with high sugar diets could be at a greater risk of developing the degenerative neurological condition.

About 70 per cent of the estimated 413,000 Australians with dementia have Alzheimer’s, and more than 240 new cases of dementia are diagnosed each day, according to Alzheimer’s Australia.

Research from the University of Bath found excess glucose damages a vital enzyme involved with inflammation response to the early stage of the disease.

Abnormally high blood sugar levels, or hyperglycaemia, is a well-known characteristic of diabetes and obesity.

Diabetes patients have an increased risk of developing Alzheimer’s, where abnormal proteins aggregate to form ‘plaque’ and ‘tangles’ in the brain.

It was already known that glucose and its breakdown products can damage proteins in cells through a reaction called glycation.

But now scientists have unravelled the specific molecular link between glucose and Alzheimer’s disease.

Studying people both with and without Alzheimers, they found in the early stages of Alzheimer’s, glycation damages an enzyme called MIF (macrophage migration inhibitory factor).

MIF plays a role in immune response and insulin regulation, and glycation limits its powers.

So researchers believe that inhibition and reduction of MIF activity may be the “tipping point” in disease progression.

As the disease progresses, the glycation of these enzymes increases.

Professor Jean van den Elsen, from the University of Bath’s department of biology and biochemistry, said: “We’ve shown that this enzyme is already modified by glucose in the brains of individuals at the early stages of Alzheimer’s disease.

The next step is to see if similar changes can be detected in blood.

Dr Omar Kassaar, from the University of Bath, said excess sugar was “well known to be bad for us when it comes to diabetes and obesity, but this potential link with Alzheimer’s disease is yet another reason that we should be controlling our sugar intake in our diets.”

The work is published in the journal Scientific Reports.

More than 6.4 million Australians will be diagnosed with dementia in the next 40 years, at a cost of more than $1 trillion, unless significant medical breakthroughs are made, Alzheimer’s Australia’s recent Economic Cost of Dementia2016-2056 report forecasts.